I can recall what The Professor himself said:
"If I wrote the epic as real life, then the Ring would have been seized and used against Sauron; the Dark Tower would not have been destroyed, but occupied; a new Dark Lord would have arisen; Saruman would have found the missing elements of Ring-lore in the confusion; and hobbits would have been enslaved by both sides, not being trusted by either."
Not a direct quote, but gistful...
By "werewolf-like metamorphosis" I was referring not to the dual personalities scene, but rather to the Smeagol/Deagol flashback in ROTK, where they morph Serkis into Gollum in a montage of steps.